Coiled tubing is a technology that has been expanding its range of application since its introduction to the oil industry in the 1960's. Its ability to pass through completion tubulars and the wide array of tools and technologies that can be used in conjunction with it make it a very versatile technology.
Typical coiled tubing apparatus includes surface pumping facilities, a coiled tubing string mounted on a reel, a method to convey the coiled tubing into and out of the wellbore, such as an injector head or the like, and surface control apparatus at the wellhead. Coiled tubing has been utilized for performing subterranean formation operations, well treatment operations, and/or well intervention operations in existing wellbores such as, but not limited to, hydraulic fracturing, matrix acidizing, milling, perforating, coiled tubing drilling, and the like.
In coiled tubing operations, the process whereby downhole tools are transferred from atmospheric pressure to wellbore pressure is referred to as coiled tubing deployment. Coiled tubing deployment is typically accomplished using a riser long enough that the entire downhole tool may be placed inside the riser at once, and then pressurizing the riser after placing the tool therein. However, for longer tools this is not feasible due to limitations on the maximum height for a coiled tubing injector (depending on charge pressure and crane availability). In such an instance, the downhole tools are lowered into the well in sections and hung off of the blowout preventer (BOP) rams using a deployment bar that matches the coiled tubing diameter. These deployment bar sections are placed in a riser and may be conveyed in by coiled tubing, wireline, or slickline.
It remains desirable to provide improvements in oilfield surface equipment and/or downhole assemblies such as, but not limited to, methods and/or systems for deploying coiled tubing into wellbores whereby the deployment of coiled tubing may be improved by providing interlocks to prevent opening of the blowout preventer when high pressure is sensed below the blowout preventer.